for the most part mobile devices, and must derive
their electrical power from on-board batteries, a
motor-generator, a fuel cell, or possibly solar
panels, with batteries being the main source.
Lead-acid, gelled electrolyte, and nickel-cadmium
batteries were the only choices a decade or so
ago. Nickel-metal hydride (NiMH) became popular

80 SERVO 02.2010

FIGURE 3. Lunar

Regolith Digging
Contestant.

about 10 years ago as a higher power density and
lighter source.

Today, many robot systems utilize lithium-ion
(lithium cobalt oxide or Li-ion) batteries that offer
two to four times the power density/mass capacity
as NiMH batteries, two to three times faster
charging, and a longer cycle life. Soon those
swollen battery packs on the backs of larger
bipedal robots and other service robots will shrink
into smaller internal structures. The driving force
behind the development of these batteries has
been the ‘green’ trend.

Exactly What are
Service Robots?

The International Federation of Robotics
defines service robots in this way:

“Service robots have no strict internationally
accepted definition, which, among other things,
delimits them from other types of equipment, in
particular, the manipulating industrial robot. IFR,
however, has adopted a preliminary definition.”
“A service robot is a robot which operates
semi or fully autonomously to perform services
useful to the well-being of humans and
equipment, excluding manufacturing operations.”
“With this definition, manipulating industrial
robots could also be regarded as service robots,
provided they are installed in non-manufacturing
operations. Service robots may or may not be
equipped with an arm structure as is the industrial
robot. Often, but not always, the service robots
are mobile. In some cases, service robots consist
of a mobile platform on which one or several arms
are attached and controlled in the same mode as
the arms of the industrial robot.”

“Because of their multitude of forms and
structures, as well as application areas, service
robots are not easy to define.”

Well, that definition is about as clear as the
answer to “what is a robot” with “I can’t define
what a robot is; I just know what a robot is when
I see one.” Besides, the third paragraph in the
definition seems to center on any type of robot
not used in manufacturing operations.

It’s a Tough Sell for
Robots Today

Despite the many new robot products making
today’s headlines — including the popular robot
hamsters that hit last Christmas — the recession is
hitting robot sales very hard in all industrialized
countries. Recent articles about Japan’s robotics